Expansion-shield.



No. 685,321. Patented. Nov. 5, I901. J. H. 600K.

, EXPANSION SHIELD.

Appiication filed Mar. 14, 1901.

(Ho Madel.)

U ITE STATES" PATENT ()FFICE.

JOHN H. coon, OF NEW-YORK, N. in, AssIcN'o-R'To HENRY-n. NEwn LL,

' or PLAINFI'ELD', NEW JERSEY.

Exenuslo'N-smsro.

srnorrrcerron forming part of Letters Patent N 685,821 dated. rial-at...5, 1901. Application filed March 14, 1901. Serial n6. 61,091. (Nomodel.)

:To all whom it may concern:

Be it known that I, J OHN H. 000K, a citi- -zen of the United States,residing in the city "of New York, borough of Brooklyn, county of '5Kings, State of New York, have invented certain new and usefulImprovements in Expansion-Shields, of which the following is aspecification, reference being had to the drawings accoipipanying andforming part of the same. M3. present invention relates toexpansionshields by which a threaded bolt is adapted to be secured tomarble, slate t-iling, or other fragile material by'being forced intosuch an expansion-shield fitted in a holein such ma terial.

In the accompanying drawings, in which like reference-letters refer tosame parts throughout the several views, Figure 1 is an axial sectionthrough my shield, taken on the no line 1 1 of Fig. 2. Fig. 2 is an endelevation of my shield looking at the 'head of the shield.

Fig. '3 is an elevation looking at the other endv of the shield, theshield in these figures being in itsexpand'ed position. Fig. 4; is anaxial section of my shield when in a closed position. Fig.5 is an endelevation of the same, and Fig. 6 is a perspective view show:

ing the shield in its expanded-position.

. My expansion-shield is, formed of expansio his material, such as softmetal, so that the various parts of the same can yield and accommodatethemselves to anycavity into which the shield may be inserted. Theshield consists of a tubular head A at one end, which is connected withfour longitudinally-extending sections 'or members B. The shield isformed in the, expanded position shown in Figs. 1 to 3, and the head' ofthe shield and members B have an exterior conical surface,

4c the diameter of the head being considerably less than the diameter ofthe members B at f the other end of the shield when such shield isexpanded. The head is formed with a conical central bore F, whichcommunicates with 4.5 a cylindrical bore extending axially through therest of, the shield, there being grooves D formed on the interior of themembers B. These grooves are intended to form the seat for thescrew-bolt which is to be inserted-into 5b the expansion shield,.and inorder that such bolt may be more readily inserted and grip the shieldmore firmly a screw-thread E is.

cut on the interior surface of the members 15 throughout the length ofthe same. As is clearly seen in Fig.3, the sections or members B areseparated from each other by longitudinal slots 0, extending up to thehead A. Since these slots are of considerable width, the sections B arequite narrow where they engage the bolt on the inside of the shield. Theexterior of the shield isformed with suitable projections G to assistthe shield in gripping the material into which it is inserted.

After the shield has been formed, as above described, in any suitableway the sections 13 are bent inward, so as to come practically incontact at the outer ends of the same, so

that the shield will take the position shown:

in Figs. t and 5 and. so that it will have a substantially cylindricalform for more readyinsertion into a cylindrical hole. As is seen-in Fig.4, the central cavity through the shield 'is'tapering under theseconditions, and the outer end of the same adjacent to the head Ais ofthesame diameter as in the expanded shield, as shown in Fig. 1; It willbe noted also that the radial thickness of the members B variesfrom endto end of' the same, such members being considerably thicker at theirfree ends than they are adjacent the head A.

The operation of ,my shield is as follows: A substantially cylindricalhole is formed in any ma terialsuch as brick, tiling,or Woodto which itis desired to secure a screw-bolt,

and the shield while in the contracted position shown in Fig. 4: isinserted into said hole,

the head of'the shield A being outward. A 1

screw'bolt is then readily inserted int-0 the conical cavity in the headof' the shield and readily engages the threads out on the inside of themembersB. The screw is driven home as far as desirable into the shieldand forces its way gradually alongthe tapering bore between the membersB, keeping in engagement with the interior threads out upon the same andat the same timeforces such members radially outward. Since the screw engages the members 13 upon the comparatively narrow inner edges of thesame, the forcewith which the members are driven outradially is muchless than would be the "case if the screw were imengagem ex t-with suchmembers of the-same than at threaded bore in alinement with the conicalhole in the head, such shield havinga'ronghened conical exterior surfaceso that the ri dial thickness of the shield is less at the head theother end, whereby the slotted body of the shield is arranged to becontracted to a substantially cylindrical form.

9. In an expansionshield formed of expansible material, a tubular headformed with a conical hole, a longitudinally-slotted body attached tothe same formed with a roughened conical exterior surface and a threadedcylindrical inner herein alinement with the con-.-

ical hole in the head, the slots in the body of the shield forining ribswhichare adapted to engage a screw inserted into the boreof'the shieldthroughout only a portion of the periphery of the same whereby theshield is arranged to be expanded with'a gentle radial pressuregradually increasing away from said tubular head bya screw engaging thethreads upon the bore of the shield 10. In an expansion-shieldconsisting of a tubular block ing a cavity formed th'erein,said blockbeing threaded-throughout the length or such cavityto receive a boltinserted in 'said cavity of soft expansihle material hav g and beingformed to engage said bolt through only a small portion of the peripheryof the same so as to yieldingly force the expansible material outward. r

11. In an expansion-shield consisting of a block of soft expansihlematerial having a tubular head, a plurality of sections connectedtherewith, and separated from each other by longitudinal slots andprovided with interior,

projections formed by the intersection of the slots,

engaged hya screw.

JOHN H. COOK:

Witnesses:

HARRY L. DUNCAN, JOHN' N. MOORE.

said sections being threaded internally throughout their entire extentto be readily

